jacobian calculation for triagular element

Radioss Geek

Hi,

I have a single order triangular element created between nodes at (0,0,0), (5,0,0) and (4.2,0.2,0).

The element looks far away from its ideal shape but the jacobian value comes out to be 1 in HM Element quality panel. How can I explain this?

Adriano_Koga

Jacobian (or jacobian determinant) is always 1 for first order tria/tetra elements, that has only 1 integration point. Jacobian can be different than 1 for 2nd order elements.

Please take a look at Altair ebook for Pratical Aspects of FEA.

 

Both first and second order solid and plate elements are included in this check; however, first order tria and tetra elements always have a Jacobian value of 1.0.